CVE-2021-2136 in WebLogic Server
Summary
by MITRE • 04/23/2021
Vulnerability in the Oracle WebLogic Server product of Oracle Fusion Middleware (component: Core). Supported versions that are affected are 12.1.3.0.0, 12.2.1.3.0, 12.2.1.4.0 and 14.1.1.0.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via IIOP to compromise Oracle WebLogic Server. Successful attacks of this vulnerability can result in takeover of Oracle WebLogic Server. CVSS 3.1 Base Score 9.8 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
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Analysis
by VulDB Data Team • 04/25/2021
The vulnerability identified as CVE-2021-2136 represents a critical security flaw in Oracle WebLogic Server that affects multiple versions including 12.1.3.0.0, 12.2.1.3.0, 12.2.1.4.0, and 14.1.1.0.0 within the Core component of Oracle Fusion Middleware. This vulnerability operates through the Internet Inter-ORB Protocol IIOP which serves as a communication mechanism for distributed object requests in Java-based applications. The flaw enables an unauthenticated attacker to gain unauthorized access to the target server through network-based attacks, making it particularly dangerous as it requires no prior authentication credentials to exploit.
The technical nature of this vulnerability stems from insufficient validation of IIOP requests within the WebLogic Server implementation, allowing attackers to craft malicious requests that can bypass normal authentication mechanisms. This weakness falls under the category of insufficient authentication checks and can be classified as CWE-287, which addresses improper handling of authentication tokens or credentials. The vulnerability's exploitability is enhanced by its low attack complexity and lack of required privileges, as indicated by the CVSS 3.1 score of 9.8 that reflects high impact across confidentiality, integrity, and availability domains. The attack vector specifically utilizes network access through IIOP protocols, making it accessible to remote attackers without requiring physical access to the target system.
The operational impact of successfully exploiting CVE-2021-2136 can be devastating for organizations relying on Oracle WebLogic Server infrastructure. An attacker who successfully compromises the server gains complete control over the target system, potentially enabling them to execute arbitrary code, modify or delete critical data, and disrupt services entirely. This level of compromise can lead to significant data breaches, service interruptions, and potential lateral movement within the network infrastructure. The vulnerability's classification as easily exploitable means that attackers can potentially compromise systems quickly and with minimal technical expertise, making it a prime target for automated exploitation campaigns. Organizations may experience complete system takeover, allowing unauthorized access to sensitive business data and critical enterprise applications that typically run on WebLogic Server platforms.
Mitigation strategies for this vulnerability should include immediate application of Oracle's security patches and updates released specifically for this CVE. Network-level protections such as firewall rules that restrict access to IIOP ports and services should be implemented to limit exposure to unauthorized networks. Organizations should also consider disabling IIOP protocols entirely if they are not actively required for business operations, as this removes the attack surface entirely. The ATT&CK framework classification for this vulnerability would include techniques related to remote code execution and privilege escalation, with potential lateral movement through the network once initial access is achieved. Regular security monitoring and vulnerability scanning should be implemented to detect any potential exploitation attempts, while network segmentation can help limit the scope of potential damage if exploitation occurs. Additionally, implementing proper access controls and network access controls specifically for WebLogic Server components can provide additional layers of defense against this type of attack vector.